Plant species distributions in fragmented landscapes of Ohio and Belize

Agriculturally dominated landscapes often include woodlots surrounded by other human-dominated vegetation types. Woodlots often change over time,  disappearing due to cutting, appearing due to land abandonment from other uses, or changing size or configuration. Within a woodlot human activity may be pronounced or minimal. We are studying 1) what makes some species more widespread (found in more woodlots) than others and 2) what makes some woodlots more diverse than others. Our hypotheses are that species vary markedly in their frequency across woodlots and that woodlots vary markedly in the number of species they contain. Further, we hypotheses that these trends will be similar in west central Ohio and in northern Belize. We will examine the role of species characteristics such as dispersal agent and longevity and woodlot characteristics such as size and habitat heterogeneity in determining these patterns. For the Ohio site we looked at the distribution of 30 species in 14 woodlots in Greene County, dominated by corn, soybeans, and housing developments. Woodlots contained 7-28 of the target species; species were found in 0-14 sites. Species found in all woodlots included Lonicera maackii, Alliaria petiolata, Galium aparine, Podophyllum peltatum and Claytonia virginica. Species found in few woodlots included Asarum canadense and Geranium maculatum. Although exceptions occur, ant-dispersed species tended to more restricted than species with vertebrate dispersal. For the Belize site we looked at the distribution of 36 species in 19 woodlots varying in age and size in the Corozal District. Other land uses included sugar cane and papaya orchards. Woodlots contained 10-36 species; species were found in 1-19 sites. Older woodlots had more species than younger woodlots; larger woodlots had more species than smaller woodlots. Species characteristics were related to success but not consistently. The patterns from the two sites contained many similarities.